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As-needed Cialis 20 mg follows a 10 mg start

6 min readReviewed 21 August 2026. Updated

At a glance

Page typeNote
Featured strength20 mg as needed
Usual start10 mg
ReviewerCamille Rousseau, MD

The recommended starting dose of tadalafil for use as needed is 10 mg, taken prior to anticipated sexual activity. The dose may be increased to 20 mg or decreased to 5 mg. The maximum recommended dosing frequency is once per day.

Calendar strip and tadalafil blister on brief note about weekend planning

01How the 20 mg as-needed tablet is labelled

The recommended starting dose of tadalafil for use as needed is 10 mg, taken prior to anticipated sexual activity. The dose may be increased to 20 mg or decreased to 5 mg, based on individual efficacy and tolerability. The maximum recommended dosing frequency is once per day.

Tadalafil for use as needed was shown to improve erectile function compared to placebo up to 36 hours following dosing. Some people take one tadalafil tablet 30 minutes before sex. Sexual stimulation is needed.

CIALIS tablets are 2.5 mg, 5 mg, 10 mg, and 20 mg. Do not split tadalafil tablets; the entire dose should be taken. Tadalafil is not indicated for use in females. Do not combine CIALIS with other PDE5 inhibitors or other ED therapies.

02Reactions logged at 2 percent or greater

Most common adverse reactions at 2% or greater include headache, dyspepsia, back pain, myalgia, nasal congestion, flushing, and pain in limb. In tadalafil clinical pharmacology trials, back pain or myalgia generally occurred 12 to 24 hours after dosing and typically resolved within 48 hours.

CIALIS is contraindicated if there is a known serious hypersensitivity to tadalafil, CIALIS, or ADCIRCA. Store according to the carton.

03Plasma times after an as-needed swallow

After a dose, the maximum tadalafil concentration is reached between 30 minutes and 6 hours. The median time to maximum concentration is about 2 hours. The mean terminal half-life is 17.5 hours in healthy subjects.

Tadalafil may be taken with or without food.5 mg.

How to cite this page - Vancouver style

Halo Medix Medicines Reference. As-needed Cialis 20 mg follows a 10 mg start [Internet]. Montreal: Halo Medix; 21 August 2026 [cited 2026 Aug 21]. Available from: https://halomedix.com/notes/tadalafil-weekend-planning/

Sources and how this page was reviewed

  1. DailyMed - CIALIS (tadalafil) tablets
  2. FDA - Cialis prescribing information

Numbers come from the cited labels. Dr. Camille Rousseau, MD reads the draft, then the page is dated. See the method page and editorial standards.

Reader questions

('Readers around Montreal asked about the 20 mg as-needed tablet. ', 'Answers follow the U.S. Cialis label.')

Mathieu Roy, Plateau asks

Is 20 mg the first as-needed Cialis tablet for most men?

Reply from our reviewer

The recommended starting dose of tadalafil for use as needed is 10 mg, taken prior to anticipated sexual activity. The dose may be increased to 20 mg or decreased to 5 mg, based on individual efficacy and tolerability. The maximum recommended dosing frequency is once per day. CIALIS tablets are 2.5 mg, 5 mg, 10 mg, and 20 mg. Do not split tadalafil tablets; the entire dose should be taken. Sexual stimulation is needed. Tadalafil is not indicated for use in females. This note features the 20 mg increase. The 10 mg start remains the labelled first as-needed mark for most patients.

Sana El-Hajj, Laval asks

How long after 20 mg was erectile function still better than placebo?

Reply from our reviewer

Tadalafil for use as needed was shown to improve erectile function compared to placebo up to 36 hours following dosing. Some people take one tadalafil tablet 30 minutes before sex. After a dose, the maximum tadalafil concentration is reached between 30 minutes and 6 hours. The median time to maximum concentration is about 2 hours. The mean terminal half-life is 17.5 hours in healthy subjects. Tadalafil may be taken with or without food. Do not combine CIALIS with other PDE5 inhibitors or other ED therapies.

Olivier Gagné, Rosemont asks

Can a missed 20 mg be made up with a second tablet the same day?

Reply from our reviewer

Do not take a double dose of tadalafil to make up a missed dose. The maximum recommended dosing frequency is once per day. Most common adverse reactions at 2% or greater include headache, dyspepsia, back pain, myalgia, nasal congestion, flushing, and pain in limb. Back pain or myalgia generally occurred 12 to 24 hours after dosing and typically resolved within 48 hours.

Hélène Côté, NDG asks

Is the 20 mg tablet written for women?

Reply from our reviewer

Tadalafil is not indicated for use in females. CIALIS is indicated for erectile dysfunction. CIALIS is contraindicated if there is a known serious hypersensitivity to tadalafil, CIALIS, or ADCIRCA. Sexual stimulation is needed. 5 mg once-daily start.

Nadia Bensalem, Saint-Lambert asks

What temperature is written on the U.S. Cialis carton?

Reply from our reviewer

Store at 25 C (77 F); excursions permitted to 15 to 30 C (59 to 86 F). Keep out of reach of children. CIALIS tablets contain 2.5 mg, 5 mg, 10 mg, or 20 mg of tadalafil. Four strengths of almond-shaped tablets are available in different sizes and different shades of yellow. Do not split tadalafil tablets; the entire dose should be taken. If you miss a dose, you may take it when you remember but do not take more than one dose per day. CIALIS may be taken without regard to food. This note features the 20 mg as-needed increase.

Patrick Chen, Brossard asks

How is tadalafil cleared after a 20 mg swallow?

Reply from our reviewer

The mean terminal half-life is 17.5 hours in healthy subjects. The mean oral clearance for tadalafil is 2.5 L/hr. Tadalafil is excreted predominantly as metabolites, mainly in the feces (approximately 61% of the dose) and to a lesser extent in the urine (approximately 36% of the dose). After a dose, the maximum tadalafil concentration is reached between 30 minutes and 6 hours. The median time to maximum concentration is about 2 hours. The mean apparent volume of distribution following oral administration is approximately 63 L. At therapeutic concentrations, 94% of tadalafil in plasma is bound to proteins. Absolute bioavailability of tadalafil following oral dosing has not been determined.

Sophie El-Khatib, Dollard-des-Ormeaux asks

Which reactions sat at 2 percent or greater on the Cialis label?

Reply from our reviewer

Most common adverse reactions at 2% or greater include headache, dyspepsia, back pain, myalgia, nasal congestion, flushing, and pain in limb. Tadalafil was administered to over 9000 men during clinical trials worldwide. In tadalafil clinical pharmacology trials, back pain or myalgia generally occurred 12 to 24 hours after dosing and typically resolved within 48 hours. When medical treatment was necessary, acetaminophen or non-steroidal anti-inflammatory drugs were generally effective. CIALIS is contraindicated if there is a known serious hypersensitivity to tadalafil, CIALIS, or ADCIRCA. Across all studies with any CIALIS dose, reports of changes in color vision were rare (<0.1% of patients).